C JS. Beecher — Reconstractio)i of a Cretaceous Dinosaur. :517 



organs of prehension. The present mounted specimen of Claosauriis 

 shows the left scapula lying on the ribs nearly i)arallel to the direc- 

 tion of the vertebra} (Plate XLIV, figure 1). The reason for this is, 

 primarily, that the bone is placed where it was found in the rock in 

 connection with the body, and as so much of the remaining portions 

 of the skeleton was in a normal position, it seemed safe to assume 

 that the scapula, also, was in its true place. It is likewise of the 

 greatest significance that, in the specimen of Igiianodon figured by 

 Dupont,^ the position of the scapula as it was lying in the rock is 

 ]»recisely identical and not as subsequently placed in the mounted 

 specimen (see figures 3, 6). It is quite possible that the present 



Figure 6. — Skeleton of Ignanodon ha positiou in the rock. After Dupont. 



scapula belongs higher up, though still retaining its parallel position, 

 but the actual location does not involve any question of judgment, 

 since the bone is Avhere found. The scapulae in most birds (compare 

 skeleton of Penguin) are almost })arallel to the vertebral axis, and a 

 similar position among the Ornithopoda would not be unexpected. 



The structure of the pollex in Claosaurus shows that it was proba- 

 bly opposable to the other digits and functioned as a true thumb. 

 This with the slender form of the whole manus indicates that the 

 fore limbs were properly organs of prehension. To be thus used to 

 the greatest advantage, the position of the scapulae parallel with the 

 axis would be an obvious structural benefit. 



There are a number of minor anatomical differences between the 

 actual specimen and its original pictorial representation which could 

 be discussed, but those here mentioned are believed to be the more 

 important ones. These discrepancies have arisen largely from the 

 difficulty in construing the whole or parts of a skeleton before the 

 actual articulation of the bones is attempted. 



